VF TUNER Toyota Generation 4 ECU Kit Installation Guide

VF TUNER Toyota Generation 4 ECU Kit

Specifications

• Product : VF TUNER Generation 4 Toyota ECU
• Compatibility : Toyota vehicles with V35 3.5L twin-turbo engine
• Features : Load-based ECU tuning, boost pressure modification

Product Usage Instructions

• Understanding the Load Based ECU
  The Toyota V35 3.5L twin turbo engine calibration relies on controlling Load and Torque for performance. Unlike older calibrations, there are no direct boost targets. Boost and power are derived from various load tables including references, limiters, or targets for different scenarios such as temperatures and enrichments.

• Tuning Load Basics
  To achieve additional power, focus on modifying the Primary Maximum Allowed Boost Pressure Global 1 and 2 tables. These tables directly impact boost pressure and can increase power output. However, be aware that modifying these tables may be limited by other load tables.

• Raising the Primary Boost Target
  By adjusting the Primary Boost Target, you can ensure that the minimum load is always achieved without faults.

Understanding the Load Based ECU

• Toyota’s new V35 3.5L twin turbo engine calibration is designed based on controlling Load and Torque. Unlike simpler calibrations and ECUs from before, there are NO direct “boost targets” or “boost tables.” Instead, the ECU derives boost and power from various load tables.
• These Load tables either are references, limiters, or targets. There are Load controls for many different scenarios including Oil Temperatures, Intake Air Temperatures, Intercooler Temperatures, Catalyst Temperatures, etc. Most are temperature or enrichment-based.
• Understanding and modifying these Load Control tables is how you can surely achieve more power with these engines.
• The stock calibration has a base load limit of around 200 (All load tables stock). Several tables need to be modified to get around this limit.
• As you approach these load tables you may notice that some contradict one another, or one limit is lower than what is already achievable in stock form. This is because some of these load tables are active ONLY under certain safety / limp / high temp / high-pressure conditions.

Tuning tip: You should only modify the necessary amount of load tables to achieve your target power goal and leave other safety-based tables in stock form.

Tuning Load Basics

There are a few primary Load tables that can be modified to achieve additional power right away without modifying any other tables. These are the Primary Maximum Allowed Boost Pressure Global 1 and 2 tables. These are Load Limit tables that modify BOOST PRESSURE directly.

Raising these tables can directly raise BOOST Pressure and achieve more power.

NOTE : you will then be limited by other load tables. So, this table cannot be raised “indefinitely” or past the hard coded load cap.

Generally, engine load will further be capped by other load tables after these are modified. These load tables should also be modified (raising target / load limits about 320 has no additional limit effect. 320 is a hard coded load limit)

Generation 4 Toyota ECU Tuning Guide

Raising the Primary Boost Target (minimum) no Faults can ensure that your MINIMUM amount of load is always achieved

Increasing Primary Boost Target (low) will need to be raised to achieve higher boost pressure / target load.

NOTE : you must also raise the Load Cap table for this same table to achieve above 240 engine load.

Boost and Load are FURTHER capped by Boost Pressure Modifier for Ignition Efficiency calculations (engine knock based). The lower the efficiency of the ignition is, the lower the load limit will be. NOTE: this table is used to cap load dependent on ignition calculations. Ignition efficiency is calculated based on learned knock. Lower values = MORE knock and less efficiency. Therefore, it is important to modify this table with the understanding that it will RAISE boost / load even when ignition efficiency is lower and therefore, more knocks may be present. Higher octane should be used in these cases.

There are 2 LOAD CAP tables (KCLV Dependent Ignition Correction for Load) that will reduce load based on KCLV (knock learn). The higher the value of Y, the MORE KNOCKING is occurring and therefore Load is being reduced.

There are 2 load tables (Boost/Load Limit 220 #1 and 2) that are being tested and seem to affect total allowable load at or around full throttle demand. These tables Cap / Limit the total load under this condition (requested full throttle). These tables should be raised for full throttle power output to be increased.

There are several load limiters, however not all need to be modified to achieve greater power output. Primarily there is a Load Limit Max table that is used for airflow calculations. This table should be increased only as much as necessary to achieve higher throttle opening.

NOTE , increasing the values too far can result in throttle DTCs.

Understanding Load Limiters

The Tundra and other LOAD-based ECUs designed by Toyota have a 320 Load Limit cap. This limit cannot be raised at this time. The limit consists of a reference table (320 table) and many instances of a CODE check on load. These code checks perform this basic task:

1. Get value from load table
2. Is value from table > 320? If yes, load = 320. If no, load = value from load table.

This code check CANNOT be modified by increasing ANY table in the ECU. There is currently no way around this limit. We have not seen this limit being achieved with stock turbos at this time, so there is nothing to be concerned about at this time.

Throttle Limiting for Load

The ECU will achieve target load generally by two methods: Boost pressure and Throttle Angle.
If all load caps have been raised and you are still achieving some throttle limitation, you should consider that it is further being limited by Driver- Demand tables (Base Request Map 1). Increasing the values in these tables can increase demanded throttle angle (be sure to check the 2D Load limit max, so that it is not being limited by that 2D table).

Torque Limitations

• There are several Torque Limiters in the ECU that may need modified to achieve additional power. These tables are found in the Load Control section AND the Safety Based FUEL section (as there are load cap tables for safety fueling).
• During high power demand, these tables may become active and limit the load depending on multiple conditions/criteria. Not all are known at this time. Modifying / increasing these tables can eliminate these load / power reductions.

Note : These tables are still CODE capped at 320.

Tuning Boost

• The V35A uses various models for the stock turbochargers to achieve desired airflow. This airflow is then converted into a load and torque value. There are no basic “target boost pressure” tables. As a result, you cannot “raise boost pressure” to an exact amount that you want just by modifying a table to do so.
• Instead, the ECU will target whatever boost pressure it feels is necessary to achieve a DESIRED LOAD. ALL desired and target load tables are referenced in the map list. To raise boost pressure, you should INCREASE load limits.
• Increase load limits incrementally and DATALOG the boost pressure achieved so that you can create a calibration that achieves your desired boost pressure and target load.
• NOTE: We do NOT recommend blindly increasing load caps on all tables. This can cause unstable boost, unstable load targets, DTCs, and various other issues.
• NOTE: If you modify a load table that contradicts another, that table may no longer be referenced at all.
• For example, if you set “Load Limit ECT” to 0, and set Load Limit IAT to 300, the ECT table may no longer be used whatsoever. It is important to target and understand that the desired load values should be realistic. Setting values to “1000” will achieve no desired effect above the 320 cap.

Tuning Fuel Basics

Tuning fuel is relatively simple once you understand that fuel demand is almost solely based on Driver Input and Catalyst Temperatures. To tune fuel, there are some basic steps that must be followed, and a basic understanding of how power enrichment is demanded. Richer AFR / more fuel is NOT achieved simply by pushing the accelerator pedal down, or even flooring it. Instead, richer AFR is achieved based on the calculated Exhaust Gas Temperature (EGT) and catalyst temperatures.

NOTE : there are 2 completely separate AFR tables that are used in 2 different modes (direct injection active only, or twin injection active). You should set them both to be the same when modifying one or the other, as does the OEM calibration.

Understanding this will help you tune AFR and achieve richer AFR quicker when needed. To do so, the following steps can be done: 1) Modifying the Estimates for Enrichment. The ECU Estimates EGT and increases fuel as needed to protect the catalysts. These values can be LOWERED to achieve more fuel sooner as the EGT estimate will be achieved quicker. This should be done for Estimates for Enrichment Table 2 values as well.

You should also consider the LOAD based and LAMBDA based tables for increasing fuel. LOWERING the values in the LOAD based will force the logic to increase fueling sooner based on the desired LOWER load you have presented in the table. In stock form the table is set to the load cap (320) and effectively not used.

Only AFTER you have modified your temperature models and datalogged the result to confirm achieving your desired enrichment times, should you then modify the ENRICHMENT tables to achieve your target enrichment.

NOTE : the stock O2 sensors are WRAF (wide range air fuel) and can read very rich mixtures. The stock O2 sensors can be relied upon for datalogging AFR / lambda.

The tables (Target Enrichment 1 and 2) can be used to derive a Lambda value by the following formula: (1 – x) = Lambda. You’ll notice that the OEM values can request a desired lambda as low as 0.4x. This is normal, and not a cause for concern as the ECU will use this value to dump tremendous amounts of fuel near the RPM limiter. Leaning out or enriching these values as necessary can be done to achieve a desired power output.

Tuning Ignition Basics

All ignition tables in the ECU is included in the current map list. Currently, not all tables are understood at which time they are used or referenced. Generally, we recommend follow the OEM formula and table setup where many of the tables are just copies of one another.

IMPORTANT TUNING TIP ! Several Ignition tables, notably the “BY AFR” tables are 4D Tables! Check the BOTTOM LEFT of the table where it shows “AFR” as this is the Z axis for the 4D table. You can CHANGE this axis by clicking the drop-down tab and it will show the next table for this axis. This is IMPORANT for accurate ignition tuning.

Tuning Valve Timing

• Tuning Intake cam timing (Base Intake Valve Angle Target) is relatively simple as the desired value in the table is what can be achieved / targeted directly in most cases (except in idle). Idle tuning will come at a later date.
• Exhaust cam timing is more complex, and we are still working on the logic for this. The stock 3D tables are NOT always used at full or high load, and there are several 1D and 2D states / limiters / and targets for the exhaust cam. We are expanding our knowledge on this part of the code and tuning for the exhaust cam will come at a later time.

Note: the higher the value is on the intake cam the LESS the value you will be able to achieve on the exhaust cam, as there are CODE controls that limit overlap.

Future Updates
More tuning information will come as we further our understanding of the logic of this ECU. A separate tuning guide document will be created for the 2.4L engine as the calibration has some slight differences that must be understood.

Please send all your questions to: support@ovtune.zendesk.com

FAQ

Q: Can I modify all load tables to increase power?
A: It is recommended to modify only the necessary load tables to reach your power goal and keep safety-based tables unchanged.

Q: What is the base load limit of the stock calibration?
A: The stock calibration has a base load limit of around 200.

Q: Are there any specific precautions to take when tuning load tables?
A: Yes, make sure to understand the impact of modifying load tables on overall engine performance and safety limits.

References

• Zendesk: The Complete Customer Service Solution

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